I recently learned about Spousal IRA's and Spousal Roth IRA's.
I never understood about Roth IRA's or saw much benefit from them. However I now have a circumstance where one is useful, but even though I am well past retirement age, I cannot take money from one at this time because of the the 5 year limit.
I would encourage younger folks, even though a Roth IRA might not have any purpose for them at this time, to allocate a few hundred dollars from their annual IRA contributions and open a bank or credit union roth IRA so that the 5 year rule will not be a constraint at some point in the future if a Roth IRA becomes beneficial.
Someone doing this should recognize that the money going to the Roth will reduce the amount they can put in the Traditional IRA in that year.